How to determine if a php array is empty

In PHP development, determining whether an array is empty is a common requirement. Sometimes we need to perform specific operations in the code, but if the array is empty, there is no need to perform these operations, so it is necessary to determine whether the array is empty. In this article, we will detail how to tell if a PHP array is empty.

Arrays in PHP are a very useful data structure that are often used to store large amounts of data. We can usually use the following methods to determine whether a PHP array is empty:

1. empty() function

empty() function can be used to determine whether a variable is Empty, it also works for arrays. Returns true if the array is empty, false otherwise. The following is a sample code that uses the empty() function to determine whether a PHP array is empty:

<?php
    $array = array();
    if (empty($array)) {
        echo "数组为空";
    } else {
        echo "数组不为空";
    }
?>

2. count() function

The count() function can be used to obtain the array The number of elements. If the array is empty, 0 is returned. Therefore, we can use the count() function to determine whether the PHP array is empty. The following is a sample code that uses the count() function to determine whether a PHP array is empty:

<?php
    $array = array();
    if (count($array) == 0) {
        echo "数组为空";
    } else {
        echo "数组不为空";
    }
?>

3. sizeof() function

sizeof() function and count() function are basic Same, they can be used to get the number of elements in an array. The usage is basically the same. The following is a sample code that uses the sizeof() function to determine whether a PHP array is empty:

<?php
    $array = array();
    if (sizeof($array) == 0) {
        echo "数组为空";
    } else {
        echo "数组不为空";
    }
?>

4. isset() function

isset() function is used to determine whether a variable is defined and not empty, can also be used for arrays. Returns false if the array is empty, true otherwise. The following is a sample code that uses the isset() function to determine whether a PHP array is empty:

<?php
    $array = array();
    if (isset($array) && !empty($array)) {
        echo "数组不为空";
    } else {
        echo "数组为空";
    }
?>

In summary, the above methods can all determine whether a PHP array is empty. Their usage scope and methods are slightly different, and developers should choose the corresponding method for judgment based on actual needs.

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